New ‘State of the Air’ Report Finds the Milwaukee Metro Area’s Air Quality Has Worsened

The air quality in Greater Milwaukee has worsened according to the American Lung Association’s 2025 “State of the Air” report, released today. Residents are being exposed to more unhealthy ozone and particle pollution, the report finds. The Milwaukee metro area ranks 26th worst in the nation for ozone pollution with 9.5 unhealthy days per year and received an F grade. The metro area also received an F grade for particle pollution and is ranked the 50th worst in the nation with 3.8 unhealthy days per year.

The report also found that nearly half of the U.S. population, 156 million people, live in areas with unhealthy levels of air pollution. Researchers add extreme heat and wildfires contributed to the worsening air quality across much of the country.

The Lung Association’s 26th annual “State of the Air” report grades exposure to unhealthy levels of ozone air pollution and particle pollution over a three-year period (2021-2023). The report looks at the latest quality-assured air quality data from 2021-2023. Findings for the Milwaukee metro area include:

• Ground-level Ozone Pollution in the Milwaukee-Racine-Waukesha, WI metro area:
  • National Ranking: 26th worst out of 228 (26th worst in 2024 report)
  • Number of Unhealthy Days Per Year: 9.5 days per year (6.7 days per year in 2024 report)
  • Grade: F, Racine County worst in metro area (F in 2024 report)
• Short-term Particle Pollution in the Milwaukee-Racine-Waukesha, WI metro area:
  • National Ranking: 50th worst out of 223 (105th worst in 2024 report)
  • Number of Unhealthy Days Per Year: 3.8 days per year (0.3 days per year in 2024 report)
  • Grade: F, Milwaukee County worst in metro area (B in 2024 report)
• Year-Round Average Level of Particle Pollution in Milwaukee-Racine-Waukesha, WI metro area:
  • National Ranking: 59th worst in the nation (48th worst in 2024 report)
  • Grade: Failing grade, pollution levels above the federal standard

Ozone smog and particle pollution are widespread and can impact anyone’s health. Both pollutants can cause premature death and other serious health effects such as asthma attacks, heart attacks and strokes, preterm births and impaired cognitive functioning later in life. Particle pollution can also cause lung cancer.

“Unfortunately, too many people in the Greater Milwaukee area are living with unhealthy levels of ozone and particle pollution. This air pollution is a threat to human health at every stage of life – from increasing the risk of premature birth and low birth weight babies to causing or worsening lung disease,” said Molly Collins, Advocacy Director for the American Lung Association. “We urge Wisconsin policymakers to take action to improve our air quality, and we are calling on everyone to support the incredibly important work of the U.S. Environmental Protection Agency (EPA).”

Air quality in most other areas of the state also significantly worsened since last year’s report.

Highlights include: The Green Bay metro area earned failing grades for ozone and short-term particle pollution and is ranked 52nd worst for ozone and 36th worst for particle pollution; The Madison metro area fell off the nation’s cleanest cities list for short-term particle pollution and is ranked 44th worst. The area is also ranked 34th worst in the nation for ozone pollution.

On a national level, the “State of the Air” report found that 156 million people in the U.S. (46%) live in an area that received a failing grade for at least one measure of air pollution. 42.5 million people live in areas with failing grades for all three measures. The report also found that a person of color in the U.S. is more than twice as likely as a white individual to live in a community with a failing grade on all three pollution measures. Notably, Hispanic individuals are nearly three times as likely as white individuals to live in a community with three failing grades.

The Lung Association is calling on everyone to support the U.S. Environmental Protection Agency. The EPA is essential to protecting people’s health from ozone and particle pollution. Join the American Lung Association in advocating to protect EPA’s expert staff and lifesaving programs. See the full report results and take action at Lung.org/sota.

The “State of the Air” report relies on data from air quality monitors managed by state, local and Tribal air pollution control authorities in counties across the U.S. The rankings are based on the worst county in the area’s average number of unhealthy days.

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